Field of the Invention
The present invention relates to a cleaning blade which is to be used in an electrophotographic image forming apparatus, a process cartridge, and an electrophotographic image forming apparatus.
Description of the Related Art
An electrophotographic image forming apparatus includes a cleaning member configured to remove a toner remaining on an image bearing member, e.g., a photosensitive member after a toner image is transferred from the image bearing member onto a body to be transferred, e.g., a sheet or an intermediate transfer member. Of those cleaning members, a cleaning blade using a plate-like elastic member has been well known. In recent years, in order to meet the demand for improving an image quality of an electrophotographic image, attempts have been made to perform diameter reduction and spheroidization of a toner, with the result that the toner remaining on the image bearing member becomes liable to pass through the cleaning blade. Therefore, the cleaning blade is required to have more excellent cleaning performance.
In Japanese Patent Application Laid-Open No. 2001-75451, there is disclosed a cleaning blade in which the hardness of an abutment portion of the cleaning blade formed of a polyurethane elastomer is increased by increasing the concentration of an isocyanurate group of the abutment portion. There is also disclosed that, with the foregoing, friction between an image bearing member and the cleaning blade is reduced. Further, in Japanese Patent Application Laid-Open No. 2012-53311, there is disclosed a cleaning blade in which a tip end portion of the cleaning blade is subjected to hardening treatment, and further, the physical properties of an inner portion in the tip end portion subjected to the hardening treatment are regulated without impairing rubber elasticity.